The present invention relates to an apparatus and method for aligning a multiplicity of chip parts in a row and delivering them.
Known part-aligning apparatus of this kind include bulk feeders and vibrating ball feeders. Bulk feeders are roughly classified into pneumatically driven bridge breaking type and bridge breaking type using an upwardly thrust pin. With the pneumatically driven type, it is difficult to adjust the amount and direction of airflow. With the upwardly thrust pin type, whenever an operation is performed, the pin impacts the parts and so the parts tend to be easily scratched or damaged. In either type, every chip part is forced toward a funnellike exit. Therefore, if a bridge breaking operation is once performed, the bridge is immediately restored. In consequence, the efficiency at which parts are aligned is low. In the case of the vibrating ball type, any bridge is not readily formed. However, the equipment is expensive. Vibration is easily transmitted to other apparatus. Furthermore, large space is necessitated.
A part-aligning apparatus free of these problems is proposed in Japanese Unexamined Patent Publication No. 143164/1996, and comprises a cylindrical stocker for holding chip parts, an annular body disposed on the outer surface of the outer curved wall of the stocker, and a rotary disk having an annular indexing portion. This indexing portion is rotatably disposed in the gap between the outer curved wall of the stocker and the inner surface of the annular body. The indexing portion has a plurality of chip-holding recesses for seizing the chip parts individually. A chip discharge hole in communication with a chip storage portion is formed near the bottom of the outer wall of the stocker and in the path over which the chip-holding recesses are moved. In this case, movement is provided only by rotary motion and so it is easy to make an adjustment. The chip parts are less damaged. In addition, the apparatus can be easily built in smaller size.
The above-described part-aligning apparatus requires at least the stocker, the annular body, and the rotary disk. Therefore, this apparatus is complex in structure and often breaks down. It is necessary that the rotary disk be provided with chip-holding recesses arranged circumferentially, the recesses conforming to the shapes of the individual chip parts. In order to align micrometer chip parts as long as about 1 mm long, the chip-holding recesses must be processed in correspondingly small size. Hence, the apparatus is very complex in structure and laborious to machine, thus increasing the cost.
The chip parts are held one by one by the chip-holding recesses in the indexing portion of the rotary disk. As the disk turns, the chip parts are forced toward a chute. Therefore, if the chute becomes clogged or overflows for some reason, a chip part subsequently fed in will be caught in the chute. As a result, the chip part may be damaged or the apparatus itself may break down. At this time, therefore, it is necessary to quickly stop the rotary disk using a full occupation sensor.
It is an object of the present invention to provide a part-aligning apparatus that is simple in structure, less damages chip parts to be aligned, and functions well even if the chip discharge passage becomes clogged or overflows.
It is another object of the invention to provide a method of aligning chip parts without being affected by clogging of the chip discharge passage or by overflow of the chute such that the chip parts are less damaged than heretofore.
The above objects are achieved in accordance with the teachings of the invention by an apparatus comprising: a part-holding chamber for accommodating a multiplicity of chip parts; a chute groove formed at least in the inner surface of the bottom of the part-holding chamber and acting to orient the chip parts in a given direction and to cause them to slide downward; a gate port for passing the chip parts one by one, the chip parts sliding downward in a given posture along the chute groove; a discharge passage for aligning the chip parts passed through the gate port in a row and delivering the parts; and a rotary impeller having blades rotatably held in the part-holding chamber. The blade shave front end portions passing over the gate port. The blades of the impeller are rotated to urge any chip part halted in an abnormal posture in the gate port toward a direction different from a direction in which the chip parts are delivered, thus removing the clogging.
The chip part introduced into the part-holding chamber is kept on the inner surface of the bottom by gravity and falls into the chute groove. Since the chute groove is formed at a desired width, the chip part falls into the chute groove and oriented in a given direction. For example, where the chip part assumes a boxlike shape, i.e., the length is greater than the width and the height, if the width of the chute groove is set smaller than the width and the height of the chip parts, the chute groove can align the chip parts in the vertical direction. Each chute part falling into the chute groove is slid downward by gravity and brought into the gate port. If the chute part is in a correct posture (e.g., a lateral posture), the chip part passes through the gate port intact. Then, it is discharged into a discharge passage. However, if a chip part in an abnormal posture (e.g., an elevated posture) reaches the gate port, the part clogs the port. Since the blades of the rotary impeller pass over the gate port regularly, the chip part staying in the gate port is urged toward a direction different from the direction in which chip parts are discharged. The result is that the chip part is removed from the gate port or modified into normal posture. This removes the clogging. Hence, the following chip parts are allowed to be discharged from the gate port.
When a guide surface for sliding chip parts into the chute groove is provided on an inner surface of the part-holding chamber, aligning efficiency is improved, because the chip parts slide into the chute groove smoothly. A guide surface may have curved surface rather than inclined surface, as long as the guide surface can slide the chip parts into the chute groove smoothly.
Various means are conceivable as means for removing clogging. For example, where means for removing clogging are claw portions which are provided with a rotary member rotating around a horizontal axis and which rotate just above the gate port in an opposite direction to the chip parts discharging direction, clogging will be removed, because the claw portions apply power to chip parts in the opposite direction of chip parts discharging direction. Note that shapes or numbers of claw portions are not limited.
The clogging-removing means can be other than the rotary member. For instance, an air ejection nozzle or a thrust pin may be mounted near the gate port. The pin is periodically ejected or thrust to remove the clogging. The direction in which the air is ejected or the pin is thrust is not always required to be opposite to the direction in which chip parts are discharged. The former direction may be at right angles to the discharge direction.
When the rotary member is used as a clogging-removing means, clogging-removing efficiency in improved, because the chip parts which are clogged at the gate port can be easily fallen down by rotating the rotary member intermittently.
When the part-holding chamber is a cylinder-like space whose central axis is a horizontal axis, preferably, a chute groove is formed as an arc-shaped groove on an inner surface of the cylinder-like space, and claw portions of the rotary member as a clogging-removing means rotate along the groove.
In such a case, the claw portions have the following functions besides the clogging-removing function of the chip parts:
a function for dissolving the bridges of chip parts which are not slid down into the chute groove by stirring the chip parts in the part-holding chamber.
a function for forwarding all of the chip parts to the chute groove when the number of chip parts in the part-holding chamber becomes small., etc.
When a part-holding chamber comprises a fixed drum and a rotary drum, and a chute groove is an arc-shaped drum formed on an inner peripheral surface of the fixed drum, it would be preferable that a clogging-removing means is a claw portion provided on an inner surface of the rotary drum. In such a case, since the rotary drum which constructs the side wall of the part-holding chamber functions as a clogging-removing means also, the construction can be more simplified.
Further, instead of the rotary drum, rotary wings can be provided inside the part-holding chamber, clogging at the gate port can be removed by those wings.
When a chute groove is arc-shaped, it is preferable to form the discharging passage substantially in the tangent direction of the arc-shaped chute groove, and to provide the gate port at the contact point between the chute groove and the discharging passage, because the movement of the chip parts from the chute groove toward the discharging passage is smooth. It is not limited to that the discharging passage is formed in the tangent direction precisely to the chute groove, it may be rather inclined to.
In another embodiment of the invention, plural chute grooves are formed in parallel in the inner surface of the part-holding chamber, and the gate port and are formed at the lower end of each chute groove. And a plurality of discharge passages for supplying chip parts discharged from each gate port in a single line are formed. In this case, chip parts are aligned with improved efficiency.
The present invention is adapted for alignment of chip parts in a boxlike form, i.e., the length is greater than the vertical and lateral dimensions. The invention can be applied to alignment and delivery of cubic chip parts and cylindrical chip parts as well as to boxlike chip parts.
Other objects and features of the invention will appear in the course of the description thereof, which follows.